New Features

Dialog/gallery navigation

• adds "Next" and "Previous" navigation buttons to each gallery dialog modal
• updates dialog controls to include close, next, and previous buttons
• enables keyboard navigation (ArrowLeft/ArrowRight) and swipe gestures to move between dialogs
• adds new SVG arrow icons

opt-in for submenus in the main navigation

• adds new subMenu boolean option to meta.navigation for including new nav-sub.js script
• updates main-nav.njk to render submenu buttons and lists if navigation items have a submenu property.
• adds a new SVG icon (chev-down.svg) for submenu toggles
• nav-sub.js handles submenu open/close, aria attributes, ESC key, and click-outside behavior.
• updates navigation and cluster styles to support submenus, including no-JS fallbacks
• updates navigation documentation to explain how to enable and configure submenus

As usual, I'll continue iterating over this to improve. Feedback welcome!